Focal segmental glomerulosclerosis (FSGS) is a chronic renal disease seen both in idiopathic form and in association with HIV infection, heroin use, and sickle cell anemia, but always with a higher prevalence in black populations. FSGS represents a morphologic response to renal injury, but the increased prevalence of FSGS in blacks suggests a genetic component may underlie this predisposition to FSGS. We are currently establishing lymphoblastoid cell lines from three groups of patients for a genetic analysis using 300 microsatellite markers. The patient groups are: (1) 100 black patients with FSGS but without HIV infection, (2) 100 black patients with HIV associated FSGS, (3) and a control group of 200 HIV seropositive black patients without evidence of clinical renal disease. HLA loci will be detected by molecular methods and approximately 300 microsatellite markers will be tested for use in mapping by admixture disequilibrium analysis. In addition, specific candidate genes will be screened using single strand conformational and restriction fragment length polymorphisms to detect associations between specific alleles and disease category. If anonymous markers show an association with FSGS, the genomic region will be examined for the presence of additional markers that can be analyzed and for specific candidate genes located in the region of interest.